Investigating Cannabidiol and Garcinol as Antimicrobial Agents against Bacteria

A. Azzouz, K. Vig
Earlham College,
United States

Keywords: cannabis, CBD, garcinol, antimicrobial, bacteria, sustainable, medicine, tropical, creams


As pathogens keep developing antimicrobial resistance, threatening the efficacy of present medicine, a post-antibiotic era will surely be on the rise. Unfortunately, there are not many non-antibiotic treatments for bacterial infections. Therefore, it is unprecedented to research and discover new categories of effective antimicrobial substances. One particular substance that has garnered interest and popularity is Cannabidiol (CBD). CBD is one of many cannabinoids commonly found in Cannabis sativa, a herbaceous plant known to contain antibacterial properties. Since restrictions on the plant's growth and use were only recently lifted, its potential as an antimicrobial agent has not been thoroughly investigated. Another plant derivative of interest is Garcinol derived from Garcinia species, which have been used in traditional medicine in India and other eastern countries. This research aims to investigate CBD and Garcinol and their antimicrobial properties in depth. We examined the antimicrobial potential of CBD and Garcinol against Escherichia Coli (E.Coli), Staphylococcus Aureus, and Salmonella enterica serovar Typhimurium by performing various biological assays, such as Minimum Inhibitory Concentration (MIC), Plate Count, SEM Microscopy, Gene Expression, and Protein Expression. In addition, we evaluated the effects of CBD and Garcinol on human fibroblast cell proliferation using MTT and Alamar Blue colorimetric assays. Further, we investigated the change in the gene expression profile of the bacteria treated with CBD and Garcinol using qPCR with specific gene primers. We investigated antimicrobial properties in both 2D (cell plates) and 3D (polytetrafluoroethylene (PTFE) scaffolds). Our results demonstrated that CBD and Garcinol have antimicrobial properties on the studied bacteria. MIC values for CBD were 2 µg/mL, 1.5 µg/mL, and 2 µg/mL for E.Coli, Salmonella, and Staphylococcus respectively. MIC values for Garcinol were 0.1 µg/mL, 0.2 µg/mL, and 0.25 µg/mL for E.Coli, Salmonella, and Staphylococcus respectively. We observed 80 % cell viability at 0.8 µg/mL and 0.0825 µg/mL of CBD and Garcinol, respectively. MurF gene, RNAIII gene, and RHO gene were upregulated in E.Coli, Staphylococcus, and Salmonella, respectively when treated with CBD and Garcinol. In conclusion, CBD and Garcinol exhibited antimicrobial properties against both Gram +ve and Gram -ve bacteria. In the future, we aim to investigate these compounds and more much-needed antibiotic substitutes as traditional antibiotic resistance is on the rise. This work was supported by NSF-REU (DBI-2050038) to Dr. Komal Vig. We would like to thank Dr. Olufemi Ajayi for the procurement of CBD oil extract and for the tour of the industrial hemp farm and CBD oil extraction plant. We would like to thank Dr. Derrick Dean for the use of a Scanning Electron Microscope in our research.